PSI - Issue 2_A

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 3185–3193 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 000–000

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XV Portuguese Conference on Fracture, PCF 2016, 10-12 February 2016, Paço de Arcos, Portugal Thermo-mechanical modeling of a high pressure turbine blade of an airplane gas turbine engine P. Brandão a , V. Infante b , A.M. Deus c * a Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal b IDMEC, Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal c CeFEMA, Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal Abstract During their operation, modern aircraft engine components are subjected to increasingly demanding operating conditions, especially the high pressure turbine (HPT) blades. Such conditions cause these parts to undergo different types of time-dependent degradation, one of which is creep. A model using the finite element method (FEM) was developed, in order to be able to predict the creep behaviour of HPT blades. Flight data records (FDR) for a specific aircraft, provided by a commercial aviation company, were used to obtain thermal and mechanical data for three different flight cycles. In order to create the 3D model needed for the FEM analysis, a HPT blade scrap was scanned, and its chemical composition and material properties were obtained. The data that was gathered was fed into the FEM model and different simulations were run, first with a simplified 3D rectangular block shape, in order to better establish the model, and then with the real 3D mesh obtained from the blade scrap. The overall expected behaviour in terms of displacement was observed, in particular at the trailing edge of the blade. Therefore such a model can be useful in the goal of predicting turbine blade life, given a set of FDR data. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy A twin disc test rig for contact fatigue characterization of gear materials G. Meneghetti a, *, A. Terrin a,b , S. Giacometti c a University of Padova, Department of Industrial Engineering, Via Venezia 1, 35131, Padova, Italy b Carraro S.p.A., Via Olmo 37, 35010, Campodarsego (PD), Italy c OZ S.p.A , Via Monte Bianco 10, 35018, San Martino di Lupari (PD), Italy Abstract Pitting on g ar tooth flanks is one of th major causes of failure i power t ansmission . Cracks r ginate at the surface and propagate at a small depth causing the detachment of material debris, which results in craters. Pitting is detrimental as it leads to vibration, noise, loss of efficiency and eventually to the gear un-serviceability. The contact fatigue characterization of gear materials requires a great number of endurance tests on reference gears and is rarely affordable for industries. For this reason, the ISO standard 6336 suggests that tests on rolling pair of disks may be performed in order to compare the pitting durability of either different materials or manufacturing processes. However, the standard does not provide guidance about the geometry of the specimens and the correlation between the results of disc tests and actual gears durability. In this paper a twin-disc test rig is presented, that was conceived to reproduce the contact pressure and the sliding velocity of gears at one particular point along the tooth profile. A criterion for specimens design is also described. The discs were sized to resemble the working conditions experienced by sun gears mounted in the final drive of an axle for medium power Off-Highway vehicles. In particular, the Lower Point of Single Tooth Contact (LPSTC) was considered to design the tests, being the most favourable location for pitting occurrence because of the high contact pressures and unfavourable kinematic conditions. © 2016 Th Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. ens and the correlatio e c dis 2016 The Authors. Publish Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the Scientific Committee of ECF21.

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Pitting; Gears; Contact fatigue; Twin-Disc;

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

* Corresponding author. Tel.: +39-049-8276751; Fax: +39-049-8276785 E-mail address: giovanni.meneghetti@unipd.it

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21.

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Peer review under responsibility of the Scientific Committee of ECF21. 10.1016/j.prostr.2016.06.397